Hey there thank you. After doing a lot of research i think its false dyspnea caused by airway inflammation. I can still do the eliptical but not treadmill. I've seen a neurologist who told me i dont have any neuromuscular diseases just mild carpal, and have seen a gastro, pulmonologist etc.

I have also found it easier to breath when leaning forward vs sitting up straight when on the computer, sometimes even resting the bottom of my sternum against a table.
I think its LPR which is a form of GERD causing false dyspnea. if you google psuedo-dyspnea you can find an article by hannah sadaah

a) Esophagitis, or inflammation of the esophagus, is mostly caused by acid reflux, which is the backlash of stomach acid into the esophagus. Whereas the stomach is constituted like the mouth, the esophagus is constituted like the eye. A drop of lemon juice in the mouth tastes good but the same drop in the eye causes a red eye. Similarly, acid in the stomach is well tolerated because the stomach has a thick mucous coat whereas acid backlash into the esophagus burns and causes inflammation or esophagitis.

Esophagitis is like an iceberg, silent in the majority but causes symptoms in a small minority. Unaware, all of us backlash acid into the esophagus many times a day but anti-reflux defenses come to our rescue and wash the acid away. When our anti-reflux defenses fail, we develop esophagitis and some of us develop symptoms.

The common and well-known symptoms of esophagitis include heartburn, indigestion, abdominal pain, cough, chest pain, sore throat, and hoarse voice. A less known but more worrisome symptom is the feeling of shortness of breath, which usually occurs without the other, more common symptoms. Undiagnosed, this false shortness of breath or pseudo-dyspnea may lead to frequent heart and lung investigations and inappropriate treatments.

There are sensory nerve endings in the esophagus that can send false messages to the brain. When the esophagus is burned by refluxed acid, these nerve endings fool the brain into feeling short of breath, as though the lungs were not providing enough oxygen. Reacting to this feeling, the individual takes in deep sighs in an attempt to alleviate the perceived shortness of breath. But, the more and the deeper the sighs, the worse the perceived shortness of breath gets, rendering the individual restless and anxious. This restless anxiety leads the individual to pace or exercise, which temporarily relieves the shortness of breath. When motion ceases and the individual sits or lies down, the shortness of breath returns.

Treatment of this false shortness of breath relies on suppressing stomach acid and coating the esophagus with acid protecting agents. A combination of Omeprazole (or other acid suppressing medicines) plus Simethicone (or other acid protecting medicines) will give prompt relief and reassurance that there is nothing wrong with the heart or lungs.

Esophageal pseudo-dyspnea cannot be diagnosed with tests, examinations, or procedures. This diagnosis is entirely clinical, based on the history alone, and can only be confirmed with a therapeutic trial. Obtaining relief with acid suppressing and acid neutralizing agents confirms the diagnosis and cures the condition.